(1) Field of the Invention
The present invention relates generally to water jet looms and, more particularly, to an on loom dryer system for a water jet loom.
(2) Description of the Prior Art
Fabric made on a water jet loom is wet on the machine. It typically has somewhere between about 12%-14% moisture when it gets rolled up. Normal moisture regain for nylon is about 4%-5% if it""s just been produced and is sitting there dry. One problem with the fabric being wet is that you have to dry the fabric to prevent it from mildewing. If it sits over about 5-6 days, the fabric will start to mildew because there are usually no mildew preventive measures in the water. Thus, presently the normal process is to run it through the finishing unit just to dry it. However, this additional step adds about 20 cents a yard to the cost of producing the fabric.
One approach has been to keep the wet fabric in refrigerator trailers. However, in the summertime, because the amount of heat the fabric sees on the trailers, the cost can be up to $1500 a month, per trailer. If all of the production of a plant was done that way, the cost would be prohibitive. In addition, the amount of fabric that is in the process may be excessive because it must be finished within a certain period of time to keep it from mildewing.
Thus, if the fabric was already dried, it could be shipped directly to processing and get through the system a lot faster. Also, every time you can eliminate a fabric-handling step you improve the quality and reduce the cost because the drying process on the finishing unit actually creates defects in the fabric that wouldn""t be there if the process way was eliminated.
Still another problem is that if you don""t dry on the loom and just take the fabric up in the normal wet state, creases can be created because at a loom stop, particularly a long one, there is some inherent drying in the room. Specifically, the fabric sitting in the room does dry slightly and when there is some drying there is an accompanying dimensional change in the web. That slight dimensional change can result in creases as the fabric travels over rollers. If there is a part of the fabric that""s necked in and a part that hasn""t necked in, then at that transition the fabric will usually get a crease. Since in subsequent processing the fabric goes through many rolls and accumulators, the likelihood of a crease accruing is quite high.
Many different kinds of heaters have been tried to dry the fabric on the loom including radiant heaters. Also, different ways of moving the heater away from the fabric when the loom stops, by flipping it back or flipping it up to prevent overheating the fabric have been tried. However, when different types of direct heat or radiant heat were used, it was found that it was impossible to get the heat away from the fabric fast enough when the looms stopped. This causes the fabric to pucker in that section where the heat was concentrated for an extended period of time.
Also, trying to evaporate down from like between about 12%-16% down to 4% in a very short space with just infrared heat requires quite a bit of infrared heat. The energy is quite high and the problem of unexpected loom stops and removing that heat source very quickly becomes more acute. In addition, another problem is that as you apply heat to the web, the heat transfer is much different at the edges of the fabric than in the center of the web. With just infrared heat, you actually have to put in more heat at the edges than at the center to account for the heat transfer. This arrangement makes the heater process quite complicated. Because of these problems, earlier direct heating efforts have failed.
Some on loom assisted air drying has been tried before such as disclosed in U.S. Pat. No. 4,194,540, issued to Reynolds, which is hereby incorporated by reference in its entirety. The loom taught by Reynolds brings in some air underneath the roller. There is a little regenerative blower on the loom from the vacuum motor that""s rejecting hot air for the back end slot on the loom by putting air into each end of a trough. However, the volume of air is not sufficient to effectively remove enough moisture to dry the fabric nor does hot air alone have sufficient heat capacity to dry the fabric on loom. Air drying has been used off loom on a continuous air dryer. However, these dryers are similar to finishing ranges and are just as expensive to operate. So there may be no real cost saved.
Thus, even if the fabric went directly to a continuous dryer or finishing machine, since all looms have unexpected stops, the fabric is going to be more expensive and the fabric is still going to have creases. Alternatively, if you try to use any direct heating methods on the loom there are problems with adequate drying and with fabric pucker.
Thus, there remains a need for a new and improved water jet loom having an on loom dryer system which produces fully dried fabric at a significantly reduced cost while at the same time prevents both puckering and creasing.
The present invention is directed to a water jet loom having an on loom drying system. The water jet loom includes: a frame; a warp forming means; a shed fonning means; a weft inserting means; and a two mode on loom dryer system downstream from the weft inserting means. In the preferred embodiment, the two mode on loom dryer includes: a high volume air supply downstream from the weft inserting means; and a second dryer adjacent to the high volume air supply. Also, in the preferred embodiment, the second dryer will be at least one of radiant or convection heating; and a fabric web take-up means.
In the preferred embodiment, the fabric web take-up includes a frame; a plurality of rollers; and a drive means. The fabric take-up may further include a walk board and a fabric compensator. Also, in the preferred embodiment, the weft inserting means includes a jet nozzle and a jet pump.
In the preferred embodiment, the high volume air supply includes a high volume air blower impinging air onto the surface of the web; the second dryer is a radiant heater adjacent to the high volume air supply; and further includes a control system for selectively activating the radiant heater. In the most preferred embodiment, the high volume air blower is a tangential blower.
The high volume air blower preferably produces greater than about 1000 CFM per linear yard with about 2500 CFM being preferred. The high volume air blower produces air perpendicular to the fabric web.
In the preferred embodiment, the radiant heater is a radiant emitter panel that produces about 10 watts per square inch. The radiant heater is preferably spaced from the fabric surface to produce a fabric surface temperature greater than about 100xc2x0 F. and most preferably about 120xc2x0 F.
In the preferred embodiment, the radiant heater is downstream of the high volume air supply. In the most preferred embodiment, the radiant heater is opposed to the high volume air supply.
The control system may include at least one stop motion detector for determining when to deactivate the radiant heater. The apparatus may also further include a heat shield movable between the radiant heater and the fabric surface.
There is an eight second delay in starting the blower after the loom starts so the blower does not try to start when xe2x80x9cjoggingxe2x80x9d the loom.
Accordingly, one aspect of the present invention is to provide a water jet loom having an on loom drying system, the water jet loom comprising: a frame; a warp forming means; a shed forming means; a weft inserting means; and a high volume air dryer system downstream from the weft inserting means.
Another aspect of the present invention is to provide a two mode on loom dryer system for a water jet loom having a frame; a warp forming means; a shed forming means; and a weft inserting means, the dryer comprising: a high volume air supply downstream from the weft inserting means; and a second dryer adjacent to the high volume air supply, the second dryer being at least one of radiant or convection heating.
Still another aspect of the present invention is to provide a water jet loom having an on loom drying system, the water jet loom comprising: a frame; a warp forming means; a shed forming means; a weft inserting means; a two mode on loom dryer system downstream from the weft inserting means including: (i) a high volume air supply downstream from the weft inserting means; and (ii) a second dryer adjacent to the high volume air supply, the second dryer being at least one of radiant or convection heating; and a fabric web take-up means.